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HomeMy WebLinkAbout04_02_ Air_QualityCity of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-1 September 2020 ICF 0662.19 4.2 Air Quality 4.2.1 Introduction This section describes the environmental and regulatory setting for air quality. It also describes impacts associated with air quality that would result from implementation of the proposed project and mitigation for significant impacts where feasible and appropriate. 4.2.2 Environmental Setting The project site is located within the San Francisco Bay Area Air Basin (SFBAAB). Ambient air quality is affected by climatological conditions, topography, and the types and amounts of pollutants emitted. The following sections summarize how air pollution moves through the air, water, and soil within the air basin as well as how it is chemically changed in the presence of other chemicals and particles. This section also summarizes regional and local climate conditions, existing air quality conditions, and the sensitive receptors that may be affected by the project-generated emissions. 4.2.2.1 Pollutants of Concern Criteria Pollutants The federal and state governments have established ambient air quality standards for six criteria pollutants. Ozone is considered a regional pollutant because its precursors affect air quality on a regional scale. Pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and lead are considered local pollutants that tend to accumulate in the air locally. Particulate matter (PM) is both a regional and local pollutant. The primary criteria pollutants generated by the project are ozone precursors (nitrogen oxides [NOX] and reactive organic gases [ROGs]), CO, and PM.1,2,3 All criteria pollutants can have human health effects at certain concentrations. The ambient air quality standards for these pollutants are set to protect public health and the environment with an adequate margin of safety (Clean Air Act [CAA] Section 109). Epidemiological, controlled human exposure, and toxicology studies evaluate potential health and environmental effects of criteria pollutants, and form the scientific basis for new and revised ambient air quality standards. The principal characteristics of the primary criteria pollutants generated by the project, as well as possible health and environmental effects from exposure, are discussed below. 1 As discussed above, there are also ambient air quality standards for SO2, lead, sulfates, hydrogen sulfide, vinyl chloride, and visibility-reducing particles. However, these pollutants are typically associated with industrial sources, which are not included as part of the project. Accordingly, they are not evaluated further. 2 Most emissions of NOX are in the form of nitric oxide. Conversion to NO2 occurs in the atmosphere as pollutants disperse downwind. Accordingly, NO2 is not considered a local pollutant of concern for the project and is not evaluated further. 3 Reşitoğlu, Ibrahim A. 2018. NOX Pollutants from Diesel Vehicles and Trends in Control Technologies. Published November 5. DOI: 10.5772/intechopen.81112. Available: https://www.intechopen.com/online-first/nox- pollutants-from-diesel-vehicles-and-trends-in-the-control-technologies. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-2 September 2020 ICF 0662.19 Ozone, or smog, is a photochemical oxidant that is formed when ROG and NOX (both by-products of the internal combustion engine) react with sunlight. ROG compounds are made up primarily of hydrogen and carbon atoms. Internal combustion associated with motor vehicle usage is the major source of hydrocarbons. Other sources of ROG are emissions associated with the use of paints and solvents, the application of asphalt paving, and the use of household consumer products such as aerosols. The two major forms of NOX are nitric oxide (NO) and NO2. NO is a colorless, odorless gas that forms from atmospheric nitrogen and oxygen when combustion takes place under high temperature and/or high pressure. NO2 is an irritating reddish-brown gas that forms when NO and oxygen combine. In addition to serving as an integral participant in ozone formation, NOX acts as an acute respiratory irritant and increases susceptibility to respiratory pathogens. Ozone poses a higher risk to those who already suffer from respiratory diseases (e.g., asthma), such as children, older adults, and people who are active outdoors. Exposure to ozone at certain concentrations can make breathing more difficult, cause shortness of breath and coughing, inflame and damage the airways, aggravate lung diseases, increase the frequency of asthma attacks, and cause chronic obstructive pulmonary disease. Studies show associations between short-term ozone exposure and non-accidental mortality, including deaths from respiratory issues. Studies also suggest long-term exposure to ozone may increase the risk of respiratory- related deaths.4 The concentration of ozone at which health effects are observed depends on an individual’s sensitivity, level of exertion (i.e., breathing rate), and duration of exposure. Studies show large individual differences in the intensity of symptomatic responses, with one study finding no symptoms to the least responsive individual after a 2-hour exposure to 400 parts per billion of ozone and a 50 percent decrease in forced airway volume in the most responsive individual. Although the results vary, evidence suggests that sensitive populations (e.g., asthmatics) may be affected on days when the 8-hour maximum ozone concentration reaches 80 parts per billion.5 The average background level of ozone in the Bay Area is approximately 45 parts per billion.6 In addition to human health effects, ozone has been tied to crop damage, typically in the form of stunted growth, leaf discoloration, cell damage, and premature death. Ozone can also act as a corrosive and oxidant, resulting in property damage (e.g., degradation of rubber products and other materials). Carbon monoxide is a colorless, odorless, toxic gas produced by incomplete combustion of carbon substances, such as gasoline or diesel fuel. In the study area, high CO levels are of greatest concern during the winter when periods of light winds combine with ground-level temperature inversions from evening through early morning. These conditions trap pollutants near the ground, reducing the dispersion of vehicle emissions. Moreover, motor vehicles exhibit increased CO emission rates at low air temperatures. The primary adverse health effect associated with CO is 4 U.S. Environmental Protection Agency. 2018a. Ground-level Ozone Basins. Last updated: October 31. Available: https://www.epa.gov/ground-level-ozone-pollution/ground-level-ozone-basics#wwh. Accessed: January 6, 2020. 5 U.S. Environmental Protection Agency. 2016. Health Effects of Ozone in the General Population. Last updated September 12, 2016. Available: https://www.epa.gov/ozone-pollution-and-your-patients-health/health-effects- ozone-general-population. Accessed: January 6, 2020. 6 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-3 September 2020 ICF 0662.19 interference with normal oxygen transfer to the blood, which may result in tissue oxygen deprivation. Exposure to CO at high concentrations can also cause fatigue, headaches, confusion, dizziness, and chest pain. There are no ecological or environmental effects of CO at or near existing background CO levels.7 Particulate matter consists of finely divided solids or liquids (e.g., soot, dust, aerosols, fumes, mists). Two forms of particulates are generally considered: inhalable course particles, or PM10, and inhalable fine particles, or PM2.5. A particulate discharge into the atmosphere results primarily from industrial, agricultural, construction, and transportation activities. However, wind on arid landscapes also contributes substantially to local particulate loading. Particulate pollution can be transported over long distances and may affect human health adversely, especially people who are naturally sensitive or susceptible to breathing problems. Numerous studies have linked PM exposure to premature death in people with preexisting heart or lung disease, nonfatal heart attacks, an irregular heartbeat, aggravated asthma, decreased lung function, and increased respiratory symptoms. Studies show that long-term exposure to PM2.5 was associated with an increased risk of mortality, ranging from a 6 to 13 percent increased risk for every 10 micrograms per cubic meter (µg/m3) of PM2.5.8 Every 1 µg/m3 reduction in PM2.5 results in a 1 percent reduction in the mortality rate for individuals over 30 years old.9 Studies also show an increase in overall mortality of approximately 0.5 percent for every 10 mg/m3 increase in PM10 measured the day before death.10 However, PM10 levels have been greatly reduced since 1990. Peak concentrations have declined by 60 percent, and annual average values have declined by 50 percent.11 Depending on the composition, both PM10 and PM2.5 can also affect water quality and acidity, deplete soil nutrients, damage sensitive forests and crops, affect ecosystem diversity, and contribute to acid rain.12 Toxic Air Contaminants Although ambient air quality standards have been established for criteria pollutants, no ambient standards exist for toxic air contaminants (TACs). Many pollutants are identified as TACs because of their potential to increase the risk of developing cancer or because of their acute or chronic health 7 California Air Resources Board. 2020a. Carbon Monoxide & Health. Available: https://ww2.arb.ca.gov/resources/carbon-monoxide-and-health. Accessed: January 6, 2020. 8 California Air Resources Board. 2010. Estimate of Premature Deaths Associated with Fine Particle Pollution (PM2.5) in California Using a U.S. Environmental Protection Agency Methodology. August 31. Available: https://ww3.arb.ca.gov/research/health/pm-mort/pm-report_2010.pdf. Accessed: February 18, 2020. 9 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. 10 U.S. Environmental Protection Agency. 2005. Final Report: The National Morbidity, Mortality, and Air Pollution Study: Morbidity and Mortality from Air Pollution in the United States. Last updated February 18, 2020. Available: https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.highlight/abstract/2399/report/F. Accessed: January 6, 2020. 11 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. 12 U.S. Environmental Protection Agency. 2018b. Particulate Matter (PM) Pollution. Late updated: June 2018. Available: https://www.epa.gov/pm-pollution/health-and-environmental-effects-particulate-matter-pm. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-4 September 2020 ICF 0662.19 risks. For TACs that are known or suspected carcinogens, the California Air Resources Board (CARB) has consistently found that there are no levels or thresholds below which exposure is risk free. Individual TACs vary greatly in the risks they present. At a given level of exposure, one TAC may pose a hazard that is many times greater than another. In California, TACs are identified and their toxicity is studied by the Office of Environmental Health Hazard Assessment (OEHHA). The primary TACs of concern associated with the project are asbestos and diesel particulate matter (DPM). Asbestos is the name given to several naturally occurring fibrous silicate minerals. Before the adverse health effects of asbestos were identified, asbestos was widely used as insulation and fireproofing in buildings, and it can still be found in some older buildings. It is also found in its natural state in rock or soil. The inhalation of asbestos fibers into the lungs can result in a variety of adverse health effects, including inflammation of the lungs, respiratory ailments (e.g., asbestosis, which is scarring of lung tissue that results in constricted breathing), and cancer (e.g., lung cancer and mesothelioma, which is cancer of the linings of the lungs and abdomen). DPM is generated by diesel-fueled equipment and vehicles. Within the Bay Area, the Bay Area Air Quality Management District (BAAQMD) has found that of all controlled TACs, emissions of DPM are responsible for about 82 percent of the total ambient cancer risk.13 Short-term exposure to DPM can cause acute irritation (e.g., eye, throat, and bronchial), neurophysiological symptoms (e.g., lightheadedness and nausea), and respiratory symptoms (e.g., cough and phlegm). The U.S. Environmental Protect Agency (EPA) has determined that diesel exhaust is “likely to be carcinogenic to humans by inhalation.”14 Odors Offensive odors can be unpleasant and lead to citizen complaints to local governments and air districts. According to CARB’s Air Quality and Land Use Handbook,15 land uses associated with odor complaints are typically sewage treatment plants, landfills, recycling facilities, manufacturing plants, and agricultural areas. CARB provides recommended screening distances for siting new receptors near existing odor sources. 4.2.2.2 Climate and Meteorology Although the primary factors that determine air quality are the locations of air pollutant sources and the amount of pollutants emitted from those sources, meteorological conditions and topography are also important factors. Atmospheric conditions, such as wind speed, wind direction, and air temperature gradients, interact with the physical features of the landscape to determine the movement and dispersal of air pollutants. Unique geographic features define the 15 air basins throughout the state, each with its own distinctive regional climate. The air quality study area is located on the San Francisco Peninsula in the SFBAAB. 13 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. 14 U.S. Environmental Protection Agency. 2003. Diesel Engine Exhaust. CASRN N.A. February 28. Available: https://cfpub.epa.gov/ncea/iris/iris_documents/documents/subst/0642_summary.pdf#nameddest=woe. Accessed: January 6, 2020. 15 California Air Resources Board. 2005. Air Quality and Land Use Handbook: A Community Health Perspective. April. Available: https://ww3.arb.ca.gov/ch/handbook.pdf. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-5 September 2020 ICF 0662.19 The Peninsula subregion extends from northwest of San José to the Golden Gate Bridge. The Santa Cruz Mountains run along the center of the peninsula, with elevations above 2,000 feet at the southern end but decreasing to 500 feet in South San Francisco. Coastal towns experience a high incidence of cool, foggy weather in the summer. San Francisco lies at the northern end of the peninsula. Because most of South San Francisco’s topography is below 200 feet, marine air can flow easily across most of the City, making its climate cool and windy. Cities in the southeastern peninsula experience warmer temperatures and fewer foggy days because the marine layer is blocked by the ridgeline to the west. The regional climate within the SFBAAB is considered semi-arid, characterized by warm summers, mild winters, infrequent seasonal rainfall, moderate onshore breezes in the daytime, and moderate humidity. A wide range of meteorological and emissions-related sources, such as the dense population centers, heavy vehicular traffic, and industrial activity, influence air quality in the SFBAAB. Annual average wind speeds range from 5 to 10 mph throughout the peninsula. The tendency is for the higher wind speeds to be found along the western coast. However, winds on the east side of the peninsula can also be high in certain locales because low-lying areas in the mountains, at San Bruno Gap and Crystal Springs Gap, commonly allow the marine layer to pass across the peninsula. The prevailing winds are westerly along the peninsula's western coastline. Individual sites can show significant differences, however. For example, Fort Funston in western San Francisco County shows a southwesterly wind pattern, while Pillar Point in San Mateo County to the south shows a northwesterly wind pattern. Sites on the east side of the mountains also show a westerly pattern, although their wind patterns are influenced by local topographic features. That is, an increase in elevation of a few hundred feet will induce flows around that feature instead of over it during stable atmospheric conditions. This can change the wind pattern by as much as 90 degrees over short distances. On mornings without a strong pressure gradient, areas on the east side of the peninsula often experience easterly flows in the surface layer. These are induced by upslope flows on the east- facing slopes and the bay breeze. The bay breeze is rarely seen after noon because the stronger sea breeze dominates the flow pattern. On the peninsula, there are two important gaps in the Santa Cruz Mountains. The larger of the two is San Bruno Gap, extending from Fort Funston on the ocean side to San Francisco International Airport on the bay side. Because the gap is oriented in the same northwest-to-southeast direction as the prevailing winds, and because elevations along the gap are under 200 feet, marine air is easily able to penetrate into the bay. The other gap in the Santa Cruz Mountains is Crystal Springs Gap, located along State Route 92 between Half Moon Bay and San Carlos. The low point is 900 feet, but elevations reach 1,500 feet north and south of the gap. As the sea breeze strengthens on summer afternoons, the gap permits maritime air to pass across the mountains. Its cooling effect is commonly seen from San Mateo to Redwood City. Rainfall totals on the east side of the peninsula are somewhat lower than those on the west side, with South San Francisco reporting an average of 20.8 inches per year. On the west side, Half Moon Bay reports 25 inches per year. Areas in the Santa Cruz Mountains report significantly higher rainfall totals, especially west of the ridge line, because of induced condensation from orographic lifting, proximity to a moisture source, and fog drip. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-6 September 2020 ICF 0662.19 Air pollution potential is lower in the northern portion of the peninsula because winds are generally fast enough to carry pollutants away before they can accumulate. The average maximum daily summertime and wintertime temperatures in South San Francisco are in the low 70s and mid-50s, respectively. The average minimum daily summertime and wintertime temperatures in South San Francisco are in the mid-50s and low 40s, respectively.16 4.2.2.3 Existing Air Quality Conditions Ambient Criteria Pollutant Concentrations A number of ambient air quality monitoring stations are located in the SFBAAB to monitor progress toward attainment of the National Ambient Air Quality Standards (NAAQS) and California Ambient Air Quality Standards (CAAQS). The NAAQS and CAAQS are discussed further under Regulatory Framework. There are no monitoring stations in the City. The nearest monitoring station is the San Francisco-Arkansas Street monitoring station, approximately 7.2 miles north of the project site. Table 4.2-1 summarizes data regarding criteria air pollutant levels at the San Francisco-Arkansas Street monitoring station between 2016 and 2018, the last 3 years with complete data. Table 4.2-1 shows that the San Francisco-Arkansas Street monitoring station recorded violations of the federal PM2.5 standard in 2017 and 2018 and state PM10 standard in 2017. Federal and state standards for other pollutants were not exceeded. Violations of the ambient air quality standards for PM indicate that certain individuals, if exposed to this pollutant, may experience health effects, such as increased incidences of cardiovascular and respiratory ailments. Table 4.2-1. Ambient Air Quality Data at the San Francisco-Arkansas Monitoring Station (2016–2018) Pollutant Standards 2016 2017 2018 Ozone (O3) Maximum 1-hour concentration (ppm) 0.070 0.087 0.065 Maximum 8-hour concentration (ppm) 0.057 0.054 0.049 Number of days standard exceededa CAAQS 1-hour standard (> 0.09 ppm) 0 0 0 CAAQS 8-hour standard (> 0.070 ppm) 0 0 0 NAAQS 8-hour standard (> 0.070 ppm) 0 0 0 Carbon Monoxide (CO) Maximum 8-hour concentration (ppm) 1.1 1.4 1.6 Maximum 1-hour concentration (ppm) 1.7 2.5 1.9 Number of days standard exceededa NAAQS 8-hour standard (> 9 ppm) 0 0 0 CAAQS 8-hour standard (> 9.0 ppm) 0 0 0 NAAQS 1-hour standard (> 35 ppm) 0 0 0 CAAQS 1-hour standard (> 20 ppm) 0 0 0 16 Weather Channel. 2020. South San Francisco, CA, Monthly Weather. Available: https://weather.com/weather/ monthly/l/58e3526471350bc59bfa920168f6bd001aa43f998b0af74fe60bea4e7ce80a23. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-7 September 2020 ICF 0662.19 Pollutant Standards 2016 2017 2018 Nitrogen Dioxide (NO2) State maximum 1-hour concentration (ppb) 58 73 68 State second-highest 1-hour concentration (ppb) 57 66 65 Annual average concentration (ppb) 10 11 11 Number of days standard exceededa CAAQS 1-hour (180 ppb) 0 0 0 Particulate Matter (PM10) Nationalb maximum 24-hour concentration (µg/m3) 35.7 75.9 40.9 Nationalb second-highest 24-hour concentration (µg/m3) 27.9 52.7 35.7 Statec maximum 24-hour concentration (µg/m3) 29.0 77.0 43.0 Statec second-highest 24-hour concentration (µg/m3) 28.0 53.0 37.0 National annual average concentration (µg/m3) 8.8 11.0 10.0 State annual average concentration (µg/m3)d 17 22 22 Measured number of days standard exceededa NAAQS 24-hour standard (> 150 µg/m3) 0 0 0 CAAQS 24-hour standard (> 50 µg/m3) 0 2 0 Fine Particulate Matter (PM2.5) Nationale maximum 24-hour concentration (µg/m3) 19.6 49.9 177.4 Nationale second-highest 24-hour concentration (µg/m3) 19.3 49.7 145.4 Statef maximum 24-hour concentration (µg/m3) 19.6 49.9 177.4 Statef second-highest 24-hour concentration (µg/m3) 19.3 49.7 145.4 National annual average concentration (µg/m3) 7.5 9.7 11.6 State annual average concentration (µg/m3) * 9.7 11.6 Measured number of days standard exceededa NAAQS 24-hour standard (> 35 µg/m3) 0 7 14 Sources: California Air Resources Board. 2020b. iADAM: Air Quality Data Statistics – Top 4 Summary (2016–2018, San Francisco County, 10 Arkansas Street). Available: https://www.arb.ca.gov/adam/topfour/topfourdisplay.php. Accessed: January 6, 2020. U.S. Environmental Protection Agency. 2018c. Outdoor Air Quality Data. Monitor Values Reports (Carbon Monoxide, 2016–2018, San Francisco County). Last updated: July 31. Available: https://www.epa.gov/outdoor-air-quality- data/monitor-values-report. Accessed: January 6, 2020. Notes: ppb = parts per billion; ppm = parts per million NAAQS = National Ambient Air Quality Standards CAAQS = California Ambient Air Quality Standards µg/m3 = micrograms per cubic meter mg/m3 = milligrams per cubic meter * = insufficient data available to determine the value a An exceedance is not necessarily related to a violation of the standard. b National statistics are based on standard-conditions data. In addition, national statistics are based on samplers, using federal reference or equivalent methods. c State statistics are based on approved local samplers and local-conditions data. d State criteria for ensuring that data are adequately complete for calculating valid annual averages are more stringent than the national criteria. e National statistics are based on samplers, using federal reference or equivalent methods. f State statistics are based on local approved samplers. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-8 September 2020 ICF 0662.19 Existing TAC Sources and Health Risks Existing TAC sources within 1,000 feet of the project site include stationary sources and the Caltrain right-of-way. Stationary sources include generators owned by AstraZeneca Pharmaceuticals, Alexandria Real Estate Equities, Health Plan of San Mateo, Life Technologies, the City of South San Francisco Water Quality Plant, Boston Properties, 425 Eccles, HCP Oyster Point, and Five Prime Therapeutics.17 The Caltrain right-of-way is approximately 800 feet northwest of the project site. Regional Attainment Status Local monitoring data are used to designate areas as nonattainment, maintenance, attainment, or unclassified areas for the ambient air quality standards. The four designations are defined below. Table 4.2-2 summarizes the attainment status of San Mateo County. l Nonattainment—Assigned to areas where monitored pollutant concentrations consistently violate the standard in question. l Maintenance—Assigned to areas where monitored pollutant concentrations exceeded the standard in question in the past but are no longer in violation of that standard. l Attainment—Assigned to areas where pollutant concentrations meet the standard in question over a designated period of time. l Unclassified—Assigned to areas where data are insufficient for determining whether a pollutant is violating the standard in question. Table 4.2-2. Federal and State Ambient Air Quality Attainment Status for San Mateo County Criteria Pollutant Federal Designation State Designation Ozone (8-hour) Marginal nonattainment Nonattainment Carbon monoxide (CO) Attainment Attainment Particulate matter (PM10) Attainment Nonattainment Fine particulate matter (PM2.5) Attainment Nonattainment Nitrogen dioxide (NO2) Attainment Attainment Sulfur dioxide (SO2) Attainment Attainment Lead Attainment Attainment Sulfates (no federal standard) Attainment Hydrogen sulfide (no federal standard) Unclassified Visibility-reducing particles (no federal standard) Unclassified Source: California Air Resources Board. 2019. Area Designation Maps/State and National (San Mateo County). Last reviewed: October 24, 2019. Available: https://ww3.arb.ca.gov/desig/adm/adm.htm. Accessed: January 6, 2020. U.S. Environmental Protection Agency. 2019. December 31. Nonattainment Areas for Criteria Pollutants (Greenbook) (San Mateo County). Available: https://www.epa.gov/green-book. Accessed: January 6, 2020. 17 Bay Area Air Quality Management District. 2018. Permitted Stationary Source Risk and Hazards. Available: https://baaqmd.maps.arcgis.com/apps/webappviewer/index.html?id=2387ae674013413f987b1071715daa65. Accessed: June 8, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-9 September 2020 ICF 0662.19 4.2.2.4 Locations of Sensitive Receptors Sensitive land uses are defined as locations where human populations, especially children, seniors, and sick persons, are located and where there is reasonable expectation of continuous human exposure according to the averaging period for the air quality standards (i.e., 24 hours, 8 hours). Typical sensitive receptors are residences, hospitals, schools, and parks. The project site includes a six-story, approximately 170,235-square-foot office building at 701 Gateway Boulevard and surface parking lots. The project site is in the Gateway Campus, an area with primarily commercial and office uses. The project site is bounded by a commercial and office building (901 Gateway Boulevard) and a surface parking lot to the north, Gateway Boulevard to the east, a surface parking lot to the south, and commercial and office buildings to the west. There are no residential or recreational sensitive receptors within 1,000 feet of the project site. The nearest residence is over 1,200 feet (0.23 mile) from the project site, and Oyster Point Park is approximately 3,100 feet (0.70 mile) northeast of the project site. There are no hospitals or schools within 0.25 mile of the project site. The nearest school is Martin Elementary School, approximately 0.8 mile west. Two day-care centers are within 0.25 mile of the project site: the One and Two Tower Place Project and the Gateway Child Development Center Peninsula. The One and Two Tower Place Project day care center is approximately 0.25 mile north, the Gateway Child Development Center Peninsula is approximately 0.19 mile (1,000 feet) from the main project construction areas. However, the Gateway Child Development Center Peninsula is approximately 0.13 mile (670 feet) from the nearest project construction area, which would be at the southern terminus of the site and include repaving and curb work, as well as some landscaping activities. 4.2.3 Regulatory Framework The federal CAA and its subsequent amendments form the basis for the nation’s air pollution control effort. EPA is responsible for implementing most aspects of the CAA. A key element of the CAA is the NAAQS for criteria pollutants. The CAA delegates enforcement of the NAAQS to the states. In California, CARB is responsible for enforcing air pollution regulations and ensuring the NAAQS and CAAQS are met. CARB, in turn, delegates regulatory authority for stationary sources and other air quality management responsibilities to local air agencies. BAAQMD is the local air agency for the project area. 4.2.3.1 Federal Clean Air Act and National Ambient Air Quality Standards The CAA was first enacted in 1963 but amended numerous times in subsequent years (1965, 1967, 1970, 1977, and 1990). The CAA establishes federal air quality standards, known as the NAAQS, for six criteria pollutants and specifies future dates for achieving compliance with the standards. The CAA also mandates that states submit and implement a State Implementation Plan (SIP) for local areas not meeting the standards. The plans must include pollution control measures that demonstrate how the standards will be met. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-10 September 2020 ICF 0662.19 The 1990 amendments to the CAA identify specific emissions reduction goals for areas not meeting the NAAQS. These amendments require both a demonstration of reasonable further progress toward attainment and incorporation of additional sanctions for failure to attain or meet interim milestones. Table 4.2-3 shows the NAAQS currently in effect for each criteria pollutant as well as the CAAQS (discussed further below). Table 4.2-3. Federal and State Ambient Air Quality Standards Criteria Pollutant Average Time California Standards National Standardsa Primary Secondary Ozone 1 hour 0.09 ppm Noneb Noneb 8 hours 0.070 ppm 0.070 ppm 0.070 ppm Carbon Monoxide 8 hours 9.0 ppm 9 ppm None 1 hour 20 ppm 35 ppm None Particulate Matter (PM10) 24 hours 50 µg/m3 150 µg/m3 150 µg/m3 Annual mean 20 µg/m3 None None Fine Particulate Matter (PM2.5) 24 hours None 35 µg/m3 35 µg/m3 Annual mean 12 µg/m3 12.0 µg/m3 15 µg/m3 Nitrogen Dioxide (NO2) Annual mean 0.030 ppm 0.053 ppm 0.053 ppm 1 hour 0.18 ppm 0.100 ppm None 4.2.3.2 Sulfur Dioxide (SO2)c Annual mean None 0.030 ppm None 24 hours 0.04 ppm 0.14 ppm None 3 hours None None 0.5 ppm 1 hour 0.25 ppm 0.075 ppm None Lead 30-day average 1.5 µg/m3 None None Calendar quarter None 1.5 µg/m3 1.5 µg/m3 3-month average None 0.15 µg/m3 0.15 µg/m3 Sulfates 24 hours 25 µg/m3 None None Visibility-reducing Particles 8 hours —d None None Hydrogen Sulfide 1 hour 0.03 ppm None None Vinyl Chloride 24 hours 0.01 ppm None None Source: California Air Resources Board. 2016. Ambient Air Quality Standards. May 4. Available: https://ww3.arb.ca.gov/research/aaqs/aaqs2.pdf. Accessed: January 6, 2020. Notes: ppm = parts per million µg/m3 = micrograms per cubic meter a National standards are divided into primary and secondary standards. Primary standards are intended to protect public health, whereas secondary standards are intended to protect public welfare and the environment. b The federal 1-hour standard of 12 parts per hundred million was in effect from 1979 through June 15, 2005. The revoked standard is referenced because it was employed for such a long period and is a benchmark for State Implementation Plans. c The annual and 24-hour National Ambient Air Quality Standards for SO2 apply for only 1 year after designation of the new 1-hour standard to those areas that were previously in nonattainment for the 24-hour and annual National Ambient Air Quality Standards. d California Ambient Air Quality Standards for visibility-reducing particles are defined by an extinction coefficient of 0.23 per kilometer (visibility of 10 miles or more due to particles when relative humidity is less than 70 percent). City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-11 September 2020 ICF 0662.19 Non-road Diesel Rule EPA has established a series of increasingly strict emission standards for new off-road diesel equipment, on-road diesel trucks, and locomotives. New equipment, including heavy-duty trucks and off-road construction equipment, is required to comply with the emission standards. Corporate Average Fuel Economy Standards The Corporate Average Fuel Economy Standards (CAFÉ standards) were first enacted in 1975 to improve the average fuel economy of cars and light-duty trucks. The National Highway Traffic Safety Administrative (NHTSA) sets the CAFÉ standards, which are regularly updated to require additional improvements in fuel economy. The standards were last updated in October 2012; the updates apply to new passenger cars, light-duty trucks, and medium-duty passenger vehicles and cover model years 2017 through 2025, with a goal of 54.5 miles per gallon by 2025. However, on August 2, 2018, NHTSA and EPA proposed an amendment to the fuel efficiency standards for passenger cars and light trucks and established new standards for model years 2021 through 2026, thereby maintaining the current 2020 standards through 2026 (Safer Affordable Fuel-Efficient [SAFE] Vehicles Rule). On September 19, 2019, EPA and NHTSA issued a final action on the One National Program Rule, which is considered Part 1 of the SAFE Vehicles Rule and a precursor to the proposed fuel efficiency standards. The One National Program Rule enables EPA and NHTSA to provide uniform nationwide fuel economy and greenhouse gas (GHG) standards by 1) clarifying that federal law preempts state and local tailpipe GHG standards, 2) affirming NHTSA’s statutory authority to set nationally applicable fuel economy standards, and 3) withdrawing California’s CAA preemption waiver to set state-specific standards. EPA and NHTSA published their decision to withdraw California’s waiver and finalized regulatory text related to the preemption on September 27, 2019 (84 Federal Register 51310). The agencies also announced that they will later publish the second part of the SAFE Vehicles Rule (i.e., the standards). California, 22 other states, the District of Columbia, and two cities filed suit against the proposed One National Program Rule on September 20, 2019 (California et al. v. United States Department of Transportation et al., 1:19-cv-02826, U.S. District Court for the District of Columbia). The lawsuit requests a “permanent injunction prohibiting defendants from implementing or relying on the preemption regulation” but does not stay its implementation during legal deliberations. Part 1 of the SAFE Vehicles Rule went into effect on November 26, 2019, and Part 2 went into effect on March 30, 2020. The rule decreases the stringency of the CAFÉ standards, calling for fuel efficiency increases of 1.5 percent each year through model year 2026 compared with the 5 percent annual increase under the 2012 standards. 4.2.3.3 State California Clean Air Act and California Ambient Air Quality Standards In 1988, the state legislature adopted the California CAA, which established a statewide air pollution control program. The California CAA requires all air districts in the state to endeavor to meet the CAAQS by the earliest practical date. Unlike the CAA, the California CAA does not set precise attainment deadlines. Instead, the California CAA establishes increasingly stringent requirements for areas that require more time to achieve the standards. The CAAQS are generally more stringent than the NAAQS and incorporate additional standards for sulfates, hydrogen sulfide, visibility- reducing particles, and vinyl chloride. The CAAQS and NAAQS are shown in Table 4.2-3. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-12 September 2020 ICF 0662.19 CARB and local air districts bear responsibility for meeting the CAAQS, which are to be achieved through district-level air quality management plans incorporated into the SIP. In California, EPA has delegated authority to prepare SIPs to CARB, which, in turn, has delegated that authority to individual air districts. CARB traditionally has established state air quality standards, maintaining oversight authority in air quality planning, developing programs for reducing emissions from motor vehicles, developing air emission inventories, collecting air quality and meteorological data, and approving SIPs. The California CAA substantially adds to the authority and responsibilities of air districts. The California CAA designates air districts as lead air quality planning agencies, requires air districts to prepare air quality plans, and grants air districts authority to implement transportation control measures. The California CAA also emphasizes the control of “indirect and area-wide sources” of air pollutant emissions. The California CAA gives local air pollution control districts explicit authority to regulate indirect sources of air pollution. Statewide Truck and Bus Regulation Originally adopted in 2005, the on-road truck and bus regulation requires heavy trucks to be retrofitted with PM filters. The regulation applies to privately and federally owned diesel-fueled trucks with a gross vehicle weight rating greater than 14,000 pounds. Compliance with the regulation can be reached through one of two paths: (1) vehicle retrofits according to engine year or (2) a phase-in schedule. The compliance paths ensure that nearly all trucks and buses will have model year 2010 engines or newer by January 2023. State Tailpipe Emission Standards Like EPA at the federal level, CARB has established a series of increasingly strict emission standards for new off-road diesel equipment and on-road diesel trucks operating in California. New equipment used to construct the project would be required to comply with the standards. Carl Moyer Program The Carl Moyer Memorial Air Quality Standards Attainment Program (Carl Moyer Program) is a voluntary program that offers grants to owners of heavy-duty vehicles and equipment. The program is a partnership between CARB and the local air districts throughout the state to reduce air pollution emissions from heavy-duty engines. Locally, the air districts administer the Carl Moyer Program. Toxic Air Contaminant Regulation California regulates TACs primarily through the Toxic Air Contaminant Identification and Control Act (Tanner Act) and the Air Toxics “Hot Spots” Information and Assessment Act of 1987 (“Hot Spots” Act). In the early 1980s, CARB established a statewide comprehensive air toxics program to reduce exposure to air toxics. The Tanner Act created California’s program to reduce exposure to air toxics. The “Hot Spots” Act supplements the Tanner Act by requiring a statewide air toxics inventory, notification of people exposed to a significant health risk, and facility plans to reduce these risks. CARB has identified DPM as a TAC and approved a comprehensive Diesel Risk Reduction Plan to reduce emissions from both new and existing diesel-fueled engines and vehicles. The goal of the plan is to reduce DPM emissions and the associated health risk by 75 percent by 2010 and by 85 City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-13 September 2020 ICF 0662.19 percent by 2020. The plan identifies 14 measures that CARB will implement over the next several years. The project would be required to comply with any applicable diesel control measures from the Diesel Risk Reduction Plan.18 4.2.3.4 Regional Bay Area Air Quality Management District At the local level, responsibilities of air quality districts include overseeing stationary-source emissions, approving permits, maintaining emissions inventories, maintaining air quality stations, overseeing agricultural burning permits, and reviewing air quality–related sections of environmental documents required by the California Environmental Quality Act (CEQA). The air quality districts are also responsible for establishing and enforcing local air quality rules and regulations that address the requirements of federal and state air quality laws and for ensuring that the NAAQS and CAAQS are met. The project falls under the jurisdiction of BAAQMD. BAAQMD has local air quality jurisdiction over projects in the SFBAAB, including San Mateo County. BAAQMD developed advisory emission thresholds to assist CEQA lead agencies in determining the level of significance of a project’s emissions, as outlined in the agency’s California Environmental Quality Act Air Quality Guidelines (CEQA Guidelines).19 BAAQMD has also adopted air quality plans to improve air quality, protect public health, and protect the climate. These include the 2017 Clean Air Plan: Spare the Air, Cool the Climate.20 The 2017 Clean Air Plan was adopted by BAAQMD on April 19, 2017. The 2017 Clean Air Plan updates the prior 2010 Bay Area ozone plan and outlines feasible measures to reduce ozone; provides a control strategy to reduce particulate matter, air toxics, and GHGs in a single, integrated plan; and establishes emission control measures to be adopted or implemented. The 2017 Clean Air Plan contains the primary goals listed below. l Protect Air Quality and Health at the Regional and Local Scale: Attain all state and national air quality standards, and eliminate disparities among Bay Area communities in cancer health risk from TACs. l Protect the Climate: Reduce Bay Area GHG emissions to 40 percent below 1990 levels by 2030 and 80 percent below 1990 levels by 2050. The 2017 Clean Air Plan is the most current applicable air quality plan for the air basin. Consistency with this plan is the basis for determining whether the project would conflict with or obstruct implementation of an air quality plan. The proposed project’s consistency with Senate Bill (SB) 32, which outlines the State’s GHG reduction goals (i.e., achieving 1990 emissions levels by 2020 and 18 California Air Resources Board. 2000. Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel- Fueled Engine and Vehicles. October. Available: https://ww3.arb.ca.gov/diesel/documents/rrpfinal.pdf. Accessed: January 6, 2020. 19 Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May. Available: https://www.baaqmd.gov/~/media/files/planning-and- research/ceqa/ceqa_guidelines_may2017-pdf.pdf?la=en. Accessed: January 6, 2020. 20 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-14 September 2020 ICF 0662.19 a level 40 percent below 1990 emissions levels by 2030), and Executive Order (EO) S-3-05, which further aims to reduce California’s GHG emissions to 80 percent below the 1990 levels by 2050, is evaluated in Section 4.7, Greenhouse Gas Emissions. In addition to air quality plans, BAAQMD also adopts rules and regulations to improve existing and future air quality. The project may be subject to the following district rules: l Regulation 2, Rule 2 (New Source Review)—This regulation contains requirements for best available control technology and emission offsets. l Regulation 2, Rule 5 (New Source Review of Toxic Air Contaminates)—This regulation outlines guidance for evaluating TAC emissions and their potential health risks. l Regulation 6, Rule 1 (Particulate Matter)—This regulation restricts emissions of PM darker than No. 1 on the Ringlemann Chart to less than 3 minutes in any 1 hour. l Regulation 7 (Odorous Substances)—This regulation establishes general odor limitations on odorous substances and specific emission limitations on certain odorous compounds. l Regulation 8, Rule 3 (Architectural Coatings)—This regulation limits the quantity of ROG in architectural coatings. l Regulation 9, Rule 6 (Nitrogen Oxides Emissions from Natural Gas–Fired Boilers and Water Heaters)—This regulation limits emissions of NOX generated by natural gas–fired boilers. l Regulation 9, Rule 8 (Stationary Internal Combustion Engines)—This regulation limits emissions of NOX and CO from stationary internal combustion engines of more than 50 horsepower. l Regulation 11, Rule 2 (Hazardous Pollutants – Asbestos Demolition, Renovation, and Manufacturing)—This regulation, which incorporates EPA’s asbestos-related National Emissions Standards for Hazardous Air Pollutants, controls emissions of asbestos to the atmosphere during demolition, renovation, and transport. 4.2.3.5 Local South San Francisco General Plan The 1999 South San Francisco General Plan (General Plan) provides a vision for long-range physical and economic development of the City, provides strategies and specific implementing actions, and establishes a basis for judging whether specific development proposals and public projects are consistent with the City of South San Francisco’s (City’s) plans and policy standards. The General Plan contains an Open Space and Conservation Element, which outlines policies related to biological resources, water quality, air quality, GHG emissions, and historic and cultural resources. The General Plan includes the following policies that are applicable to air quality: l Guiding Principle 7.3-G-1: Continue to work toward improving air quality and meeting all national and state ambient air quality standards by reducing the generation of air pollutants both from stationary and mobile sources, where feasible. l Guiding Principle 7.3-G-4: Encourage land use and transportation strategies that promote use of alternatives to the automobile for transportation, including bicycling, bus transit, and carpooling. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-15 September 2020 ICF 0662.19 l Guiding Principle 7.3-G-5: Promote clean and alternative fuel combustion in mobile equipment and vehicles. l Guiding Principle 7.3-G-6: Minimize conflicts between sensitive receptors and emissions generators by distancing them from one another. l Implementing Policy 7.3-I-1: Cooperate with BAAQMD to achieve emissions reductions for nonattainment pollutants and their precursors, including CO, ozone, and PM10, by implementation of air pollution control measures, as required by state and federal statutes. l Implementing Policy 7.3-I-2: Use the City’s development review process and CEQA regulations to evaluate and mitigate the local and cumulative effects of new development on air quality and GHG emissions. l Implementing Policy 7.3-I-3: Adopt the standard construction dust abatement measures included in BAAQMD’s CEQA Guidelines. l Implementing Policy 7.3-I-9: Promote land uses that facilitate alternative transit use, including high-density housing, mixed uses, and affordable housing served by alternative transit infrastructure. l Implementing Policy 7.3-I-13: Encourage efficient, clean energy and fuel use through collaborative programs, award programs, and incentives while removing barriers to the expansion of alternative fuel facilities and infrastructure. l Implementing Policy 7.3-I-14: Ensure that design guidelines and standards support operation of alternative fuel facilities, vehicles, and equipment. 4.2.4 Impacts and Mitigation Measures 4.2.4.1 Significance Criteria Based on Appendix G of the CEQA Guidelines, the proposed project would have an air quality impact if it would: l Conflict with or obstruct implementation of the applicable air quality plan; l Result in a cumulatively considerable net increase in any criteria pollutant for which the project region is classified as nonattainment under an applicable federal or state ambient air quality standard; l Expose sensitive receptors to substantial pollutant concentrations; or l Result in other emissions (such as those leading to odors) adversely affecting a substantial number of people. As discussed above, the pollutants that would be generated by the proposed project are associated with some form of health risk (e.g., asthma, lower respiratory problems). Regional pollutants can be transported over long distances and affect ambient air quality far from the emissions source. Localized pollutants affect ambient air quality near the emissions source. As discussed above, the primary pollutants of concern generated by the project are ozone precursors (ROG and NOX), CO, PM, and TACs (including DPM and asbestos). The emission thresholds that can be used to evaluate the significance level of regional and localized pollutants are discussed in the subsections that follow. Thresholds and guidance for evaluating potential odors associated with the project area are also presented. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-16 September 2020 ICF 0662.19 Regional Project-Generated Criteria Pollutant Emissions (Ozone Precursors and Regional Particulate Matter) This analysis evaluates the impacts of regional emissions generated by the project. It uses a two- tiered approach that considers guidance recommended by BAAQMD in its CEQA Guidelines.21 First, this analysis considers whether the project would conflict with the most recent air quality plan.22 Specifically, the impact analysis evaluates whether the project supports the primary goals of the 2017 Clean Air Plan, including applicable control measures from the plan, and whether it would disrupt or hinder implementation of any control measure from the plan. Second, calculated regional criteria pollutant emissions are compared to BAAQMD’s project-level thresholds. BAAQMD’s thresholds are summarized in Table 4.2-4 and recommended by the air district to evaluate the significance of a project’s regional criteria pollutant emissions.23,24 According to BAAQMD, projects with emissions in excess of the thresholds shown in Table 4.2-4 would be expected to have a significant cumulative impact on regional air quality because an exceedance of the thresholds is anticipated to contribute to CAAQS and NAAQS violations. Table 4.2-4. BAAQMD Project-Level Regional Criteria Pollutant Emission Thresholds Analysis Thresholds Regional criteria pollutants (construction) Reactive organic gases: 54 pounds/day Nitrogen oxides: 54 pounds/day Particulate matter: 82 pounds/day (exhaust only); compliance with best management practices (fugitive dust) Fine particulate matter: 54 pounds/day (exhaust only); compliance with best management practices (fugitive dust) Regional criteria pollutants (operations) Reactive organic gases: Same as construction Nitrogen oxides: Same as construction Particulate matter: 82 pounds/day Fine particulate matter: 54 pounds/day Source: Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/ceqa/ceqa_guidelines_may2017- pdf.pdf?la=en. Accessed: January 6, 2020. 21 Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May. Available: https://www.baaqmd.gov/~/media/files/planning-and- research/ceqa/ceqa_guidelines_may2017-pdf.pdf?la=en. Accessed: January 6, 2020. 22 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. 23 Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May. Available: https://www.baaqmd.gov/~/media/files/planning-and- research/ceqa/ceqa_guidelines_may2017-pdf.pdf?la=en. Accessed: January 6, 2020. 24 The proposed project would include office and research-and-development uses. Although the proposed office and retail uses (approximately 78,700 square feet and 12,100 square feet, respectively) would be below BAAQMD’s screening-level size for a general office building and various commercial land uses, there are no applicable screening criteria for the proposed project’s research-and-development uses (approximately 118,000 square feet). In addition, the proposed project would include demolition activities. As such, per BAAQMD, construction-related emissions of criteria pollutants should be quantified and compared to the construction-related thresholds shown in Table 4.2-5. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-17 September 2020 ICF 0662.19 Adverse health effects induced by regional criteria pollutant emissions generated by the proposed project (ozone precursors and PM) would be highly dependent on a multitude of interconnected variables (e.g., cumulative concentrations, local meteorology and atmospheric conditions, the number and character of exposed individuals [e.g., age, gender]). For these reasons, ozone precursors (ROG and NOX) contribute to the formation of ground-borne ozone on a regional scale. Emissions of ROG and NOX generated in one area may not equate to a specific ozone concentration in that same area. Similarly, some types of particulate pollution may be transported over long distances or formed through atmospheric reactions. As such, the magnitudes and locations of specific health effects from exposure to increased ozone or regional PM concentrations are the product of emissions generated by numerous sources throughout a region as opposed to a single individual project. Moreover, exposure to regional air pollution does not guarantee that an individual will experience an adverse health effect; there are large individual differences in the intensity of symptomatic responses to an air pollutant. These differences are influenced, in part, by the underlying health condition of an individual, which cannot be known. Nonetheless, emissions generated by the proposed project could increase photochemical reactions and the formation of tropospheric ozone and secondary PM, which, at certain concentrations, could lead to increased incidences of specific health consequences, such as various respiratory and cardiovascular ailments. As discussed previously, air districts develop region-specific CEQA thresholds of significance in consideration of existing air quality concentrations and attainment designations under the NAAQS and CAAQS. The NAAQS and CAAQS are informed by a wide range of scientific evidence that demonstrates there are known safe concentrations of criteria pollutants. Accordingly, the proposed project would expose receptors to substantial regional pollution if any of the thresholds summarized in Tables 4.2-4 are exceeded. Localized Project-Generated Criteria Pollutant Emissions (Carbon Monoxide and Particulate Matter) and Air Toxics (Diesel Particulate Matter) Localized pollutants generated by a project are deposited near the emissions source, potentially affecting the population near that source. Because these pollutants dissipate with distance, emissions from individual projects can result in direct and material health impacts on adjacent sensitive receptors. The localized pollutants of concern that would be generated by the project are CO, PM, and DPM. The applicable thresholds for each pollutant are described below. Carbon Monoxide Heavy traffic congestion can contribute to high levels of CO. Individuals who are exposed to such “hot spots” may have a greater likelihood of developing adverse health effects. BAAQMD has adopted screening criteria that provide a conservative indication of whether project-generated traffic would result in a CO hot spot. If the screening criteria are not met, a quantitative analysis, through site-specific dispersion modeling of project-related CO concentrations, is not necessary. The project would not result in localized violations of the CAAQS for CO. BAAQMD’s CO screening criteria are summarized below.25 25 Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/ceqa/ceqa_guidelines_ may2017-pdf.pdf?la=en. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-18 September 2020 ICF 0662.19 1. The project traffic would not increase traffic volumes at affected intersections to more than 44,000 vehicles per hour. 2. The project traffic would not increase traffic volumes at affected intersections to more than 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited (e.g., a tunnel, parking garage, bridge underpass, natural or urban street canyon, below-grade roadway). 3. The project is consistent with an applicable congestion management program established by the county congestion management agency for designated roads or highways, a regional transportation plan, and local congestion management agency plans. BAAQMD does not consider construction-generated CO to be a significant pollutant of concern because construction activities typically do not generate substantial quantities of this pollutant.26 Particulate Matter BAAQMD adopted an incremental concentration-based PM2.5 significance threshold in which a “substantial” contribution at the project level for an individual source is defined as total (i.e., exhaust and fugitive) PM2.5 concentrations exceeding 0.3 μg/m3. In addition, BAAQMD considers projects to have a cumulatively considerable PM2.5 impact if sensitive receptors are exposed to PM2.5 concentrations from local sources within 1,000 feet that exceed 0.8 μg/m3, including existing sources, project-related sources, and reasonably foreseeable future sources.27 BAAQMD has not established PM10 thresholds of significance. BAAQMD’s PM2.5 thresholds apply to both new receptors and new sources. However, BAAQMD considers fugitive PM10 from earthmoving activities to be less than significant with applicable BAAQMD Basic Construction Mitigation Measures. Diesel Particle Matter DPM has been identified as a TAC. It is particularly concerning because long-term exposure can lead to cancer, birth defects, and damage to the brain and nervous systems. BAAQMD has adopted incremental cancer and hazard thresholds to evaluate receptor exposure to single sources of DPM emissions. The “substantial” DPM threshold defined by BAAQMD is exposure of a sensitive receptor to an individual emissions source that results in an excess cancer risk level of more than 10 in 1 million or a non-cancer (i.e., chronic or acute) hazard index (HI) greater than 1.0.28 The air district also considers projects to have a cumulatively considerable DPM impact if they contribute to DPM emissions that, when combined with cumulative sources within 1,000 feet of sensitive receptors, result in excess cancer risk levels of more than 100 in 1 million or an HI greater than 10.0. BAAQMD considers projects to have a significant cumulative impact if they introduce new receptors at a location where the combined exposure level to all cumulative sources within 1,000 feet is in excess of cumulative thresholds.29 26 Ibid. 27 Ibid. 28 Ibid. 29 Ibid. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-19 September 2020 ICF 0662.19 Odors BAAQMD30 and CARB31 have identified several types of land uses as being commonly associated with odors, such as landfills, wastewater treatment facilities, and animal processing centers. BAAQMD’s CEQA Guidelines publication recommends that project analyses identify the location of existing and planned odor sources and include policies to reduce potential odor impacts in the project area. 4.2.4.2 Approach to Analysis Methods Construction Emissions Land uses that could be developed under the proposed project would generate construction-related emissions from mobile and stationary construction equipment exhaust, employee and haul truck vehicle exhaust, land clearing and material movement, paving, and the application of architectural coatings. Criteria pollutant emissions were estimated using the California Emissions Estimator Model (CalEEMod), version 2016.3.2. The construction schedule, equipment operating details, trip numbers and lengths, and material quantities were provided by the project sponsor. Daily construction emissions were estimated using these project-specific details. The construction modeling inputs and CalEEMod outputs are provided in Appendix B of this draft environmental impact report (EIR). Diesel Particulate Matter Analysis Diesel-powered construction equipment and the emergency generator during project operations would emit DPM that could expose nearby sensitive receptors to increased cancer and non-cancer risks. As noted above, the nearest sensitive receptors are located at the Gateway Child Development Center Peninsula, approximately 670 feet south of the project site. Given that the proposed project would introduce DPM emissions to an area near existing sensitive receptors, a human Health Risk Assessment (HRA) was performed using EPA’s most recent dispersion model, AERMOD (version 191901); chronic risk assessment values presented by OEHHA; and other assumptions for model inputs from BAAQMD’s Air Toxics NSR Program Health Risk Assessment Guidelines.32 The HRA takes into account OEHHA’s most recent guidance and calculation methods from the Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments.33 The HRA analyzes health risks to nearby sensitive receptors from construction activities and testing of an emergency diesel-powered generator during project operation. The human HRA consists of three parts: a DPM inventory, air dispersion modeling, and risk calculations. A description of each of these parts follows. 30 Ibid. 31 California Air Resources Board. 2005. Air Quality and Land Use Handbook: A Community Health Perspective. April. Available: https://ww3.arb.ca.gov/ch/handbook.pdf. Accessed: January 6, 2020. 32 Bay Area Air Quality Management District. 2016. Air Toxics NSR Program Health Risk Assessment Guidelines. December. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/permit- modeling/hra_guidelines_12_7_2016_clean-pdf.pdf. Accessed: August 3, 2020. 33 Office of Environmental Health Hazard Assessment. 2015. Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments. Available: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf. Accessed: August 3, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-20 September 2020 ICF 0662.19 DPM Inventory The DPM inventory includes mitigated emissions associated with short-term construction activity and emissions from testing of the emergency generator. The construction DPM inventory was assumed to be equal to the CalEEMod output results for diesel PM2.5 exhaust. The construction PM2.5 inventory was assumed to be equal to the CalEEMod output results for the sum of PM2.5 exhaust and fugitive dust. The operational DPM inventory is assumed to be equal to the CalEEMod output results for diesel PM2.5 exhaust from the generator. Air Dispersion Modeling The HRA uses EPA’s AERMOD to model annual average DPM and PM2.5 concentrations at nearby receptors. Modeling inputs, including emissions rates (in grams of pollutant emitted per second) and source characteristics (e.g., release height, stack diameter, plume width), were based on guidance provided by OEHHA and BAAQMD. Meteorological data were obtained from CARB for the San Francisco International Airport, which is the nearest monitoring station, located approximately 1.5 miles south of the project site. Construction equipment emissions were characterized as an area source (AREAPOLY) with a release height of 0.9 meters for fugitive dust emissions and 4.1 meters for all other emissions. One construction area source was modeled, which included the project site where construction is anticipated. Haul and vendor truck emissions were characterized as line/area sources (LINEAREA) with release heights of 0.9 meters for fugitive dust emissions and 3.4 meters for all other emissions. Emissions from off-road equipment were assumed to be generated throughout the construction footprint. Emissions from offsite trucks were modeled along 1,000-foot segments adjacent to the construction footprint along Gateway Boulevard and Oyster Point Boulevard. The modeling of emissions from construction activities was based on the construction hours and days (7:00 a.m. to 5:00 p.m., five days per week34) during 2020 and 2021 described in Section 3.3.2.7 in Chapter 2, Project Description, of this draft EIR. To account for plume rise associated with mechanically generated construction emissions sources for the AERMOD run, the initial vertical dimension of the area source was modeled at 3.81 meters; for the line/area sources, it was modeled at 3.16 meters. The urban dispersion option was used based on the project site’s characteristics. Offsite sensitive receptors were placed at the Gateway Child Development Center Peninsula, the only sensitive receptors within 1,000 feet of the construction work areas and haul roads. A 20-by-20-meter receptor grid was used to place receptors. Operational emissions from testing of the new 1,250 kilowatt (approximately 1,700 horsepower) diesel emergency generator were characterized as one separate vertical point source (POINT). The location of the generator in the service and loading yard south of the proposed building was estimated based on Figure 3-5 in Chapter 3, Project Description, of this draft EIR, and the urban dispersion option was assumed. The modeling of emissions from generator activities utilized a 12-hour testing window per day (8:00 a.m. to 8:00 p.m.), as testing was assumed to occur during daytime hours. Periodic testing of the generator would be completed; testing is anticipated to consist of one test per week for 30 to 45 minutes per test at a load of 100 percent for up to 50 hours per year maximum, as limited by 34 Though construction may occur some evenings and weekends, it was assumed that construction would occur during the work week (Monday-Friday) when the Gateway Child Development Center Peninsula, the only sensitive receptors within 1,000 feet of the construction work areas and haul roads, would be operational. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-21 September 2020 ICF 0662.19 the BAAQMD. Variables, including release height (3.73 meters) and stack diameter (0.21 meters), were taken from comprehensive modeling information provided by the San Joaquin Valley Air Pollution Control District for a 1,500 to 1,850 horsepower generator.35 Similar to the construction analysis, offsite sensitive receptors were placed at the Gateway Child Development Center Peninsula using a grid with 20-meter spacings. A complete list of dispersion modeling inputs is provided in Appendix B. Risk Calculations The risk calculations incorporate OEHHA’s age-specific factors that account for increased sensitivity to carcinogens during early-in-life exposure. The approach for estimating cancer risk from long-term inhalation, with exposure to carcinogens, requires calculating a range of potential doses and multiplying by cancer potency factors in units corresponding to the inverse dose to obtain a range of cancer risks. For cancer risk, the risk for each age group is calculated using the appropriate daily breathing rates, age sensitivity factors, and exposure durations. The cancer risks calculated for individual age groups are summed to estimate the cancer risk for each receptor. Chronic cancer and hazard risks were calculated using from OEHHA’s 2015 HRA guidance.36 According to BAAQMD guidance, residential cancer risks assume a 30-year exposure.37 Because mitigated emissions were used to model cancer risks and PM2.5 concentrations, unmitigated risks and PM2.5 concentrations were scaled proportionate to the unmitigated emissions inventory. The risk calculations and additional assumptions are provided in Appendix B. Operational Mobile-Source Emissions Air quality impacts from motor vehicles operating within the air basin while traveling to and from the project site were evaluated using CARB’s EMFAC2017 emissions model (version 1.02) and traffic data provided by Fehr & Peers.38 Because the office building at 701 Gateway Boulevard would remain on the site, operational mobile-source emissions associated with the office building were estimated and presented under existing (2019) and future conditions (2021).39 To determine running exhaust emissions (i.e., vehicle movement/travel), the number of employees on the project site daily and the conversion factor for vehicle miles traveled (VMT) per capita, both of which were provided by Fehr & Peers, were used to estimate total VMT with and without the proposed project. The trips generated by daily employees assumes a 26 percent alternative mode share consistent with the City/County Association of Governments (C/CAG) of San Mateo County model and analysis for other similar projects within the City and the region. Criteria pollutant emissions from vehicle running exhaust were then calculated by multiplying the VMT estimates by the appropriate emission factors provided by EMFAC2017. 35 San Joaquin Valley Air Pollution Control District. 2015. Final Staff Report. Update to District’s Risk Management Policy to Address OEHHA’s Revised Risk Assessment Guidance Document. May 28. 36 Office of Environmental Health Hazard Assessment. 2015. Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments. Available: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf. Accessed: August 3, 2020. 37 Bay Area Air Quality Management District. 2016. Air Toxics NSR Program Health Risk Assessment Guidelines. December. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/permit- modeling/hra_guidelines_12_7_2016_clean-pdf.pdf. Accessed: August 3, 2020. 38 Hawkins, Mike. Fehr & Peers. March 13, 2020—email to Jessica Viramontes: 751 Gateway Updated Transportation Materials. 39 No emissions sources are associated with the existing surface parking lots; therefore, no emissions are associated with the lot under existing conditions. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-22 September 2020 ICF 0662.19 Daily trips for the proposed project were also provided by Fehr & Peers and used to estimate a per employee trip generation rate, which was used to estimate daily trips associated with the existing building at 701 Gateway Boulevard. The number of daily trips was calculated to quantify vehicle- process emissions, such as emissions generated from vehicle starts, running losses, etc. Process emissions were then calculated by multiplying the number of daily trips by the appropriate process-specific emissions factors from EMFAC2017. The running exhaust emissions and process emissions were combined to quantify total operational emissions from the project’s use of vehicles. The analysis incorporates CARB’s criteria pollutant adjustment factors to account for Part 1 of the SAFE Vehicle Rule. The EMFAC0217 emissions factors and traffic data used in this analysis are provided in Appendix B of this draft EIR. Refer to Section 4.9, Transportation and Circulation, of this draft EIR for more details regarding the project’s trip generation. Operational Area-, Energy-, and Stationary-Source Emissions Area, energy, and stationary emissions were estimated using CalEEMod (version 2016.4.2). Area- source emissions are generated by the use of consumer products, the use of landscape maintenance equipment, and the repainting of buildings. Energy sources include the combustion of natural gas for building heating and hot water. Stationary sources include emergency backup generators. Emissions were quantified for existing and project conditions.40 Operational emissions were estimated using project-specific details (e.g., energy consumption, emergency generator specifications) and the use of CalEEMod defaults when project-specific details were not available. Similar to mobile-source emissions, area-, energy-, and stationary-source emissions were also estimated for the existing office building at 701 Gateway Boulevard. The CalEEMod output files are provided in Appendix B of this draft EIR. 4.2.4.3 Impact Evaluation Impact AQ-1: The proposed project would not conflict with or obstruct implementation of the applicable air quality plan. (Less than Significant) The CAA requires that a SIP or an air quality control plan be prepared for areas with air quality that violates the NAAQS. The SIP sets forth the strategies and pollution control measures that states will use to attain the NAAQS. The California CAA requires attainment plans to demonstrate a 5 percent per year reduction in nonattainment air pollutants or their precursors, averaged every consecutive 3-year period, unless an approved alternative measure of progress is developed. Air quality attainment plans (AQAPs) outline emissions limits and control measures to achieve and maintain these standards by the earliest practical date. The current AQAP for the SFBAAB is the 2017 Clean Air Plan.41 40 Ibid. 41 Bay Area Air Quality Management District. 2017a. Final 2017 Clean Air Plan. Adopted: April 19. Available: https://www.baaqmd.gov/~/media/files/planning-and-research/plans/2017-clean-air-plan/attachment-a_- proposed-final-cap-vol-1-pdf.pdf?la=en. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-23 September 2020 ICF 0662.19 Support of 2017 Clean Air Plan Goals The primary goals of the 2017 Clean Air Plan are to attain all state and national air quality standards and eliminate disparities among Bay Area communities in cancer health risk from toxic air contaminants. As discussed below (Impact AQ-2), the proposed project would not exceed BAAQMD’s criteria pollutant thresholds and would not result in a significant level of air pollution such that air quality within the SFBAAB would be degraded. As such, the proposed project would not contribute to increases in the CAAQS and NAAQS and, thus, would not prevent attainment of the state and national air quality standards. As further discussed below (Impact AQ-3), the project would not have a significant impact related to TACs and thus would not contribute to disparities among Bay Area communities. Therefore, based on the above analysis, the proposed project would support the primary goals of the 2017 Clean Air Plan. Support Applicable Control Measures and Their Implementation To meet the primary goals of the 2017 Clean Air Plan, specific control measures and actions are recommended. These control measures are grouped into various categories and include stationary-source measures, mobile-source measures, and transportation control measures. The 2017 Clean Air Plan recognizes that community design dictates individual travel modes and that a key long-term control strategy for reducing emissions of criteria pollutants, air toxics, and GHGs from motor vehicles is to channel future Bay Area growth into vibrant urban communities where goods and services are close at hand and people have a range of viable transportation options. To this end, the 2017 Clean Air Plan includes control measures to reduce air pollution in the SFBAAB. The measures most applicable to the proposed project are transportation, energy, building, waste management, water, and stationary-source control measures. These measures include the following: l TR1: Clean Air Teleworking Initiative – Develop teleworking best practices for employers and develop additional strategies to promote telecommuting. Promote teleworking on Spare the Air Days. l TR2: Trip Reduction Programs – Implement the regional Commuter Benefits Program (Rule 14-1), which requires employers with 50 or more Bay Area employees to provide commuter benefits. Encourage trip reduction policies and programs in local plans (e.g., general and specific plans) while providing grants to support trip reduction efforts. Encourage local governments to require mitigation of vehicle travel as part of new development approval, adopt transit benefit ordinances in order to reduce transit costs to employees, and develop innovative ways to encourage ride sharing, transit, cycling, and walking for work trips. Fund various employer-based trip reduction programs. l TR8: Ridesharing, Last-Mile Connection – Promote carpooling and vanpooling by providing funding to continue regional and local ride-sharing programs and support the expansion of car-sharing programs. Provide incentive funding for pilot projects to evaluate the feasibility and cost effectiveness of innovative ride sharing and other last-mile trip reduction strategies. Encourage employers to promote ride sharing and car sharing to their employees. l TR9: Bicycle and Pedestrian Access and Facilities – Encourage planning for bicycle and pedestrian facilities in local plans (e.g., general and specific plans) to fund bike lanes, routes, paths, and bicycle parking facilities. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-24 September 2020 ICF 0662.19 l TR13: Parking Policies – Encourage parking policies and programs in local plans (e.g., reduce minimum parking requirements), limit the supply of off-street parking in transit-oriented areas, unbundle the price of parking spaces, and support implementation of demand-based pricing (such as “SF Park”) in high-traffic areas. l TR14: Cars and Light Trucks – Commit regional clean air funds toward qualifying vehicle purchases and infrastructure development. Partner with private, local, state, and federal programs to promote the purchase and lease of battery and plug-in hybrid electric vehicles. l TR15: Public Outreach and Education – Implement the Spare the Air Every Day Campaign, including Spare the Air alerts, employer programs, community resource teams, a PEV outreach campaign, and the Spare the Air Youth Program. l TR23: Lawn and Garden Equipment – Seek additional funding to expand the Commercial Lawn and Garden Equipment Replacement Program into all nine Bay Area counties. Explore options to expand Lawn and Garden Equipment Program to cover shredders, stump grinders, and commercial turf equipment. l EN2: Decrease Electricity Demand – Work with local governments to adopt additional energy efficiency policies and programs. Support local government energy efficiency programs through best practices, model ordinances, and technical support. Work with partners to develop messaging to decrease electricity demand during peak times. l BL1: Green Buildings – Collaborate with partners such as KyotoUSA to identify energy-related improvements and opportunities for on-site renewable energy systems in school districts; investigate funding strategies to implement upgrades. Identify barriers to effective local implementation of the CALGreen (Title 24) statewide building energy code; develop solutions to improve implementation/enforcement. Work with ABAG’s BayREN program to make additional funding available for energy-related projects in the buildings sector. Engage with additional partners to target reducing emissions from specific types of buildings. l BL2: Decarbonize Buildings – Explore potential air district rulemaking options regarding the sale of fossil fuel–based space and water heating systems for both residential and commercial use. Explore incentives for property owners to replace their furnace, water heater, or natural- gas-powered appliances with zero-carbon alternatives. Update air district guidance documents to recommend that commercial and multi-family developments install ground- source heat pumps and solar hot water heaters. l BL4: Urban Heat Island Mitigation – Develop and urge adoption of a model ordinance for “cool parking” that promotes the use of cool surface treatments for new parking facilities as well as existing surface lots undergoing resurfacing. Develop and promote adoption of model building code requirements for new construction or re-roofing/roofing upgrades for commercial and residential multi-family housing. Collaborate with expert partners to perform outreach to cities and counties to make them aware of cool roofing and cool paving techniques and new tools that are available. l NW2: Urban Tree Planting – Develop or identify an existing model municipal tree planting ordinance and encourage local governments to adopt such an ordinance. Include tree planting recommendations, the air district’s technical guidance, best practices for local plans, and CEQA review. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-25 September 2020 ICF 0662.19 l WA3: Green Waste Diversion – Develop model policies to facilitate local adoption of ordinances and programs to reduce the amount of green waste going to landfills. l WA4: Recycle and Waste Reduction – Develop or identify and promote model ordinances on community-wide zero-waste goals and recycling of construction and demolition materials in commercial and public construction projects. l WR2: Support Water Conservation – Develop a list of best practices that reduce water consumption and increase on-site water recycling in new and existing buildings; incorporate into local planning guidance. l SS32: Emergency Backup Generators – Reduce emissions of diesel particulate matter and black carbon from backup generators through Draft Rule 11-18, resulting in reduced health risks to affected individuals and climate protection benefits. The proposed project would include design features that would support emissions reductions in the transportation sector. For instance, the proposed project’s TDM plan would promote transit and pedestrian connectivity and support transit priority measures (Measure TR9). The proposed project would construct new transit infrastructure, such as the new shuttle stop on the western portion of the access drive north of the existing building at 701 Gateway Boulevard, and improve the connection to the existing shuttle stop on the eastern side of Gateway Boulevard (Measures TR2 and TR8) . Other improvements, such as electric charging stations and bicycle parking, would support alternative modes of transportation within the project site (Measures TR8, TR9, and TR14). The proposed project, through its TDM plan, would monitor parking demand and require annual travel surveys as part of ongoing outreach to evaluate the effectiveness of on-site programs (e.g., telecommuting) as well as the transportation demand measures (Measures TR1, TR13, and TR15). In addition, the proposed project would implement a number of sustainability features, such as solar-ready rooftop connectivity for future installation of photovoltaic panels and Energy Star–rated and high-efficiency appliances (Measures BL1, BL2, BL4, and EN2); green infrastructure (e.g., biotreatment areas and other low-impact development) (Measures BL1 and NW2); low-flow shower heads, aerators, and toilets (Measure WR2); and waste diversion programs to reduce resource consumption as well as criteria pollutant and GHG emissions (Measures WA3 and WA4). The proposed project would be designed to meet the standards of the South San Francisco Municipal Code, CALGreen building requirements, LEED Gold certification, as well as International WELL and Fitwel Building Institute Standards (Measures BL-2 and EN2). The proposed project would result in a net tree loss (approximately 19 trees) with implementation of Mitigation Measure GHG-2. However, because younger trees typically sequester more CO2e compared to older and more mature trees, additional sequestration from newer trees planted as part of the proposed project could offset the loss of carbon sequestration from the net tree loss (Measure NW2). In addition, shrubs and biotreatment plantings as opposed to grass areas would in installed to further reduce emissions associated with lawn and garden equipment (Measure TR23). The proposed emergency generator would be subject to the permit authority of the BAAQMD to reduce associated health risks and air quality impacts (Measure SS32). Based on the above analysis, the proposed project would generally support most of the applicable control measures and their implementation identified in the 2017 Clean Air Plan to meet the plan’s primary goals. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-26 September 2020 ICF 0662.19 Disrupt or Hinder Implementation of 2017 Clean Air Plan Control Measures As discussed above, the proposed project would incorporate sustainable design features that address the transportation, energy, building, waste management, water, and stationary-source sectors. It would not disrupt, delay, or otherwise hinder implementation of any applicable control measure from the 2017 Clean Air Plan. Rather, the proposed project would support and facilitate implementation of control measures. Based on the above analysis, the proposed project would support implementation of the 2017 Clean Air Plan. Accordingly, the proposed project would not fundamentally conflict with the 2017 Clean Air Plan and would have a less-than-significant air quality impact. No mitigation measures are required. Impact AQ-2: The proposed project would not result in a cumulatively considerable net increase in any criteria pollutant for which the project region is classified as nonattainment under an applicable federal or state ambient air quality standard. (Less than Significant with Mitigation during construction; Less than Significant during operation) Construction Construction and demolition activities for the proposed project would include demolition of a surface parking lot, construction of a new building, various site improvements, and the provision of utility infrastructure. If the related entitlements are approved by the City, construction of the proposed project would begin in 2020 and occur over approximately 18 months, with anticipated completion in 2021. Construction and demolition activities would require mobile and stationary equipment as well as on-road vehicles, such as haul trucks for demolition debris and vendor trucks for deliveries. Site grading and excavation would be required for the building foundation, utilities, and landscaping. The unmitigated criteria air pollutant emissions that would be generated during construction were estimated using CalEEMod (version 2016.4.2), as presented in Table 4.2-5. Table 4.2-5. Estimated Unmitigated Criteria Pollutant Emissions from Construction of the Proposed Project (pounds/day) Construction Year ROG NOX CO PM10 PM2.5 Dust Exhaust Dust Exhaust 2020 7 68 41 1 2 < 1 2 2021 29 46 31 14 1 3 5 BAAQMD Threshold 54 54 — BMPs 82 BMPs 54 Exceed Threshold? No Yes — — No — No Source: See Appendix B of this draft EIR for CalEEMod outputs. Exceedances of the BAAQMD thresholds are underlined. ROG= reactive organic gases; NOX = nitrogen oxide; CO = carbon monoxide; PM10 = particulate matter no more than 10 microns in diameter; PM2.5 = particulate matter no more than 2.5 microns in diameter; BAAQMD = Bay Area Air Quality Management District; BMPs = best management practices. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-27 September 2020 ICF 0662.19 As shown in Table 4.2-5, construction of the proposed project would not generate ROG or PM exhaust emissions in excess of BAAQMD’s numeric thresholds. However, the proposed project would generate NOX emissions in excess of BAAQMD’s significance threshold during construction in 2020. These emissions, if left unmitigated, could contribute to a ground-level formation of ozone in the SFBAAB, which, at certain concentrations, could contribute to short- and long-term human health effects. Currently, San Mateo County does not meet the NAAQS and CAAQS for ozone or the CAAQS for PM (see Table 4.2-2). Certain individuals residing in areas that do not meet the ambient air quality standards, including South San Francisco, could be exposed to pollutant concentrations that could cause or aggravate acute and/or chronic health conditions (e.g., asthma, premature mortality). Although construction of the proposed project would contribute to future NOX emissions, maximum daily construction-generated NOX emissions would represent approximately 0.01 percent of the total NOX in the SFBAAB.42 As previously discussed, the magnitude and location of any potential change in ambient air quality, as well as the health consequences associated with additional emissions, cannot be quantified with a high level of certainty because of the dynamic and complex nature of pollutant formation and its distribution. However, it is known that public health will continue to be affected in South San Francisco as long as the region fails to meet the NAAQS and CAAQS. Implementation of Mitigation Measure AQ-1, Use Clean Diesel-Powered Equipment during Construction to Control Construction-Related NOX Emissions, would reduce construction-related NOX to below BAAQMD’s threshold, as shown in Table 4.2-6. BAAQMD’s CEQA Guidelines consider fugitive dust impacts to be less than significant with application of best management practices (BMPs). If BMPs are not implemented, the dust impact would be significant. Therefore, Mitigation Measure AQ-2, Implement BAAQMD Basic Construction Mitigation Measures, which includes BMPs to reduce fugitive dust, would be implemented to reduce impacts from construction-related fugitive dust emissions, including any cumulative impacts. As such, construction of the proposed project would not be expected to contribute a significant level of air pollution such that air quality within the SFBAAB would be degraded. Consequently, the impact from construction-generated criteria pollutant emissions would be less than significant with mitigation. Table 4.2-6. Estimated Mitigated Criteria Pollutant Emissions from Construction of the Proposed Project (pounds/day) Construction Year ROG NOX CO PM10 PM2.5 Dust Exhaust Dust Exhaust 2020 2 14 78 1 < 1 < 1 1 2021 28 11 62 14 < 1 3 4 BAAQMD Threshold 54 54 — BMPs 82 BMPs 54 Exceed Threshold? No No — — No — No Source: See Appendix B of this draft EIR for CalEEMod outputs. Emissions data in this table assume implementation of Mitigation Measure AQ-1. However, implementation of dust- related best management practices have not been explicitly quantified but would be required. ROG = reactive organic gas; NOX = nitrogen oxide; CO = carbon monoxide; PM10 = particulate matter no more than 10 microns in diameter; PM2.5 = particulate matter no more than 2.5 microns in diameter; BAAQMD = Bay Area Air Quality Management District; BMPs = best management practices. 42 NOX emissions reported in the Clean Air Plan totaled 300 tons per day. Maximum project-generated NOX emissions would be 87 pounds per day, which equates to 0.0435 ton per day. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-28 September 2020 ICF 0662.19 Mitigation Measure AQ-1: Use Clean Diesel-Powered Equipment during Construction to Control Construction-Related NOX Emissions The project sponsor shall ensure that all off-road diesel-powered equipment used during construction is equipped with EPA-approved Tier 4 Final engines. The construction contractor shall submit evidence of the use of EPA-approved Tier 4 Final engines or cleaner for project construction to the City prior to the commencement of construction activities. Mitigation Measure AQ-2: Implement BAAQMD Basic Construction Mitigation Measures The project sponsor shall require all construction contractors to implement the basic construction mitigation measures recommended by BAAQMD. The emissions reduction measures shall include, at a minimum, the following: l All exposed surfaces (e.g., parking areas, staging areas, soil piles, graded areas, unpaved access roads) shall be watered two times a day. l All haul trucks shall be covered when transporting soil, sand, or other loose material offsite. l All visible mud or dirt track-out material on adjacent public roads shall be removed using wet-power vacuum-type street sweepers at least once a day. The use of dry-power sweeping is prohibited. l All vehicle speeds shall be limited to 15 miles per hour on unpaved roads. l All roadways, driveways, and sidewalks that are to be paved shall be paved as soon as possible. Building pads shall be laid as soon as possible after grading, unless seeding or a soil binder is used. l All construction equipment shall be maintained and properly tuned in accordance with manufacturers’ specifications. All equipment shall be checked by a certified visible- emissions evaluator. l Idling times shall be minimized, either by shutting equipment off when not in use or reducing the maximum idling time to 5 minutes (as required by the California Airborne Toxics Control Measure). l Publicly visible signs shall be posted with the telephone number and name of the person to contact at the lead agency regarding dust complaints. This person shall respond and take corrective action within 48 hours. BAAQMD’s phone number shall also be visible to ensure compliance with applicable regulations. Operation Operation of the proposed project has the potential to result in air quality impacts from area, energy, mobile, and stationary sources. Area sources would include landscaping equipment; architectural coatings, with off-gassing during reapplication; and consumer products (e.g., solvents, cleaning supplies, cosmetics, toiletries). Energy sources would include on-site natural gas combustion for space and water heating. Mobile sources would include vehicle trips generated by land uses proposed within the project site. Stationary sources would include the testing of emergency generators. Each of these sources was considered in calculating the proposed project’s long-term operational emissions, which were quantified using CalEEMod for area, energy, and stationary sources and EMFAC2017 for mobile sources, as described above. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-29 September 2020 ICF 0662.19 Table 4.2-7 summarizes daily area-, energy-, mobile-, and stationary-source emissions generated under existing (2019) and 2021 conditions with the proposed project. No changes are proposed at the existing office building at 701 Gateway Boulevard; therefore, emissions estimated for the office building also represent 2021 conditions without the proposed project. To evaluate the magnitude of the change in the air quality environment due to implementation of the proposed project, emissions under 2021 conditions were compared to the emissions under existing (2019) conditions. As shown in Table 4.2-7, the proposed project would result in a net increase in ROG (approximately 11 pounds per day), NOX (26 pounds per day), CO (61 pounds per day), PM10 (59 pounds per day), and PM2.5 (16 pounds of per day). However, it would not exceed BAAQMD’s numeric thresholds. Therefore, air quality impacts from criteria pollutant emissions would be less than significant during operation. No mitigation is required. Although not required to support a less-than-significant determination or quantified for the purposes of this analysis, implementation of Mitigation Measure TR-1, as discussed in Section 4.9, Transportation and Circulation, of this draft EIR, would fund the design and construction of offsite improvements to support the proposed project’s first- and last-mile transportation demand management strategies, which would further reduce emissions. Table 4.2-7. Estimated Criteria Pollutant Emissions from Operation of the Proposed Project (pounds/day) Condition/Source ROG NOX CO PM10 PM2.5 Existing (2019) 701 Gateway (existing office building) and 751 Gateway (existing parking lot) Area Sources 4 < 1 < 1 < 1 < 1 Energy Sources < 1 1 1 <1 < 1 Mobile Sources 2 9 42 36 9 Stationary Sources 3 15 9 < 1 < 1 Totala 10 25 52 37 10 Proposed Project (2021) 701 Gateway (existing office building) Area Sources 4 < 1 < 1 < 1 < 1 Energy Sources < 1 1 1 0 0 Mobile Sources 2 7 36 36 9 Stationary Sources 3 15 9 0 0 751 Gateway (proposed R&D and office building) Area Sources 5 < 1 < 1 < 1 < 1 Energy Sources 0 1 1 0 0 Mobile Sources < 1 12 58 59 15 Stationary Sources 3 15 9 0 0 Totala 21 51 112 96 26 Net Increase with Proposed Project 2021 v. Existing 11 26 61 59 16 BAAQMD Threshold 54 54 — 82 54 Exceed Threshold? No No — No No Source: See Appendix B of this draft EIR for CalEEMod outputs and EMFAC2017 calculations. ROG= reactive organic gases; NOX = nitrogen oxide; CO = carbon monoxide; PM10 = particulate matter no more than 10 microns in diameter; PM2.5 = particulate matter no more than 2.5 microns in diameter; BAAQMD = Bay Area Air Quality Management District. a Totals may not add up because of rounding. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-30 September 2020 ICF 0662.19 The improvements would require City acquisition of private right-of-way and funding from other sources. Should the improvements recommended in Mitigation Measure TR-1 be implemented, mobile-source emissions would be less than the emissions presented in Table 4.2-7. Impact AQ-3: The proposed project would not expose sensitive receptors to substantial pollutant concentrations. (Less than Significant with Mitigation during construction; Less than Significant during operation) The primary pollutants of concern to human health generated by the proposed project are criteria pollutants and TACs. Regional Criteria Pollutants In its Sierra Club v. County of Fresno decision (6 Cal.5th 502), hereafter referred to as the Friant Ranch Decision, the California Supreme Court reviewed the long-term regional air quality analysis contained in the EIR for the proposed Community Plan Update and Friant Ranch Specific Plan (Friant Ranch Project). The Friant Ranch Project is a 942-acre master-plan development in unincorporated Fresno County and the San Joaquin Valley Air Basin, which is currently in nonattainment under the NAAQS and CAAQS for ozone and PM2.5. The court found that the EIR’s air quality analysis was inadequate because it failed to provide enough detail “for the public to translate the bare [criteria pollutant emissions] numbers provided into adverse health impacts or to understand why such a translation is not possible at this time.” According to the court’s decision, environmental documents must attempt to connect a project’s regional air quality impacts to specific health effects or explain why it is not technically feasible to perform such an analysis. As noted above, this project would not contribute to significant cumulative regional air quality impacts. Models and tools have been developed to correlate regional criteria pollutant emissions with potential community health impacts. Appendix B of this draft EIR summarizes many of these tools, describes their intended application and resolution, and determines whether they could be used to reasonably correlate project-level emissions with specific health consequences. As described in Appendix B, although some models are capable of quantifying ozone and secondary PM formation, as well as associated health effects, these tools were developed to support regional planning and policy analysis. They have limited sensitivity with respect to the small changes in criteria pollutant concentrations induced by smaller individual projects, such as a few office buildings or a single multi-family building. Therefore, translating project-generated criteria pollutants to locations where specific health effects could occur or calculating the resultant number of additional days of nonattainment cannot be achieved with any degree of accuracy for relatively small projects (relative to the regional air basin). As discussed above, BAAQMD’s regional thresholds, as presented in Table 4.2-4, consider existing air quality concentrations and attainment or nonattainment designations under the NAAQS and CAAQS. The NAAQS and CAAQS are informed by a wide range of scientific evidence that demonstrates that there are known safe concentrations of criteria pollutants. Although recognizing that air quality is a cumulative problem, BAAQMD considers projects that generate criteria pollutant and ozone precursor emissions that are below the thresholds to be minor in nature; they would not adversely affect air quality to the extent that the health-protective NAAQS or CAAQS would be exceeded. Regional emissions generated by a project could increase photochemical reactions and the formation of tropospheric ozone and secondary PM, which, at certain concentrations, could lead to increased incidences of specific health consequences. Although these health effects are associated with ozone and particulate pollution, the effects are a result of cumulative and regional emissions. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-31 September 2020 ICF 0662.19 Therefore, the project’s incremental contribution cannot be traced to specific health outcomes on a regional scale, and a quantitative correlation of project-generated regional criteria pollutant emissions to specific human health impacts is not included in this analysis. Mitigation is being applied to reduce construction emissions of ozone precursors and PM to the extent possible (i.e., Mitigation Measure AQ-1, Use Clean Diesel-Powered Equipment during Construction to Control Construction-Related NOX Emissions, and Mitigation Measure AQ-2, Implement BAAQMD Basic Construction Mitigation Measures). The project’s operational emissions would not exceed the BAAQMD thresholds. Localized Criteria Pollutants Localized criteria pollutants generated by the proposed project (e.g., fugitive dust, carbon monoxide) can be deposited near an emissions source, with the potential to affect a population near that emissions source. Although these pollutants dissipate with distance, emissions from individual projects can result in direct and material health impacts on adjacent sensitive receptors. As discussed above, the NAAQS and CAAQS are health-protective standards. They have been set at levels that are considered safe to protect public health, including the health of sensitive populations, such as asthmatics, children, and the elderly. During grading and excavation activities associated with construction, localized fugitive dust would be generated. The amount of dust generated by a project is highly variable and dependent on the size of the disturbed area at any given time, the amount of activity, soil conditions, and meteorological conditions. BAAQMD considers dust impacts to be less than significant if BAAQMD’s construction BMPs are employed to reduce such emissions. Because BAAQMD’s Basic Construction Mitigation Measures would be implemented, per Mitigation Measure AQ-2, Implement BAAQMD Basic Construction Mitigation Measures, construction-related fugitive dust emissions would be less than significant and would not expose receptors to substantial pollutant concentrations or risks. The proposed project would install a new generator on the project site, which would increase PM2.5 concentrations. The nearest sensitive receptors are located at the Gateway Child Development Center Peninsula, approximately 670 feet south of the project site; thus, the proposed project may expose receptors to substantial pollutant concentrations or risks. PM2.5 concentrations anticipated from the generator are discussed below in conjunction with toxic air contaminants. Continuous engine exhaust may elevate localized CO concentrations, resulting in hot spots. Receptors who are exposed to these CO hot spots may have a greater likelihood of developing adverse health effects. CO hot spots are typically observed at heavily congested intersections where a substantial number of gasoline-powered vehicles idle for prolonged durations throughout the day. As discussed in Section 4.2.4.1, Significance Criteria, BAAQMD has developed screening criteria to assist lead agencies in evaluating potential impacts from localized CO. The proposed project would fall within BAAQMD’s CO hot-spot screening criteria. The proposed project would not increase traffic volumes at any intersection to more than 44,000 vehicles per hour or 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited, levels specified by BAAQMD, and would be consistent with the applicable congestion management plan.43 Therefore, the proposed project would not contribute to a localized CO hot spot and would not expose receptors to substantial CO concentrations or risks. 43 Hawkins, Mike. Fehr & Peers. February 14, 2020—email to Jessica Viramontes: 751 Gateway – Transportation Schedule Check In. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-32 September 2020 ICF 0662.19 Toxic Air Contaminants The primary TAC of concern associated with the proposed project is DPM. DPM is a carcinogen emitted by diesel internal combustion engines. Construction activities would generate DPM (PM2.5 exhaust)44 that could expose adjacent receptors to significant health risks. DPM concentrations would be dramatically reduced as distance between the construction activities and sensitive receptors increases. As noted in BAAQMD’s CEQA Guidelines: Due to the variable nature of construction activity, the generation of TAC emissions in most cases would be temporary, especially considering the short amount of time such equipment is typically within an influential distance that would result in the exposure of sensitive receptors to substantial concentrations. Concentrations of mobile-source diesel PM emissions are typically reduced by 70 percent at a distance of approximately 500 feet… In addition, current models and methodologies for conducting health risk assessments are associated with longer-term exposure periods of 9, 40, and 70 years, which do not correlate well with the temporary and highly variable nature of construction activities. This results in difficulties with producing accurate estimates of health risk.45 As discussed under Impact AQ-2, Mitigation Measure AQ-1, Use Clean Diesel-Powered Equipment during Construction to Control Construction-Related NOX Emissions, and Mitigation Measure AQ-2, Implement BAAQMD Basic Construction Mitigation, are required to reduce construction emissions below air district thresholds. As such, mitigated construction emissions were modeled to determine localized health risks. Table 4.2-8 presents the maximum mitigated construction-related health risks at the Gateway Child Development Center Peninsula, the only sensitive receptors within 1,000 feet of the construction work areas and haul roads. As shown in Table 4.2-8, cancer risk, chronic hazard risk, and annual PM2.5 concentration would not exceed BAAQMD’s thresholds with implementation of Mitigation Measure AQ-1 and AQ-2. Although not anticipated with demolition of the surface parking lot, any asbestos encountered during construction would be subject to BAAQMD Regulation 11, Rule 2. Compliance with this rule would ensure a less-than-significant asbestos impact. Table 4.2-8. Mitigated Project-level Cancer and Chronic Hazard Risks and PM2.5 Concentrations During Construction Receptor Cancer Risk (cases per million) Non-Cancer Hazard Index Annual PM2.5 Concentration (µg/m3) Gateway Child Development Center Peninsula 0.6 <0.01 <0.01 Significance Threshold 10 1 0.3 Exceed Threshold? No No No Source: See Appendix B for modeling outputs and calculations. Notes: Emissions assumes the implementation of Mitigation Measure AQ-1 and AQ-2. However, implementation of dust best management practices, other than watering two times a day and limiting speed to 15 miles per hour, have not been explicitly quantified per Mitigation Measure AQ-2, but would be required. µg/m3 = micrograms per cubic meter; PM2.5 = particulate matter no more than 2.5 microns in diameter 44 Per BAAQMD guidance, PM2.5 exhaust is used as a surrogate for DPM. 45 Bay Area Air Quality Management District. 2017b. California Environmental Quality Act, Air Quality Guidelines. May Available: http://www.baaqmd.gov/~/media/files/planning-and- research/ceqa/ceqa_guidelines_may2017-pdf.pdf?la=en. Accessed: January 6, 2020. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-33 September 2020 ICF 0662.19 In addition, the proposed project would include installation and operation of a diesel-fueled generator, a new stationary source of TACs. All new stationary sources would be subject to the permit authority of the BAAQMD. The BAAQMD will not issue a permit for a new permitted source that results in an operational cancer risk in excess of 10.0 cases per million or a hazard index in excess of 1.0. However, because BAAQMD’s permit does not specifically address PM2.5, concentrations from testing of the emergency generator were modeled and results are presented in Table 4.2-9. Cancer and non-cancer health risks are presented for informational purposes only; regulatory mechanisms would ensure health risk impacts from the stationary source would be less than significant. As shown in Table 4.2-9, operation of the proposed project would not result in a significant increase in PM2.5 exhaust concentrations at the Gateway Child Development Center Peninsula, the only sensitive receptors within 1,000 feet of the construction work areas and haul roads. Table 4.2-9. Project-level Cancer and Chronic Hazard Risks and PM.5 Concentrations During Operation Receptor Cancer Risk (cases per million) Non-Cancer Hazard Index Annual PM2.5 Concentration (µg/m3) Gateway Child Development Center Peninsula 0.1 <0.01 <0.01 Significance Threshold 10 1 0.3 Exceed Threshold? No No No Source: See Appendix B for modeling outputs and calculations. Notes: µg/m3 = micrograms per cubic meter; PM2.5 = particulate matter no more than 2.5 microns in diameter Air quality impacts during construction would be less than significant with mitigation. Air quality impacts during operation would be less than significant and no mitigation is required. Impact AQ-4: The proposed project would not result in other emissions (such as those leading to odors) adversely affecting a substantial number of people. (Less than Significant) BAAQMD and CARB have identified the following types of land uses as being commonly associated with odors. Although this list is not exhaustive, it is intended to help lead agencies recognize the types of facilities where more analysis may be warranted. l Sewage treatment plants l Coffee roasters l Asphalt plants l Metal smelters l Landfills l Recycling facilities l Waste transfer stations l Petroleum refineries l Biomass operations l Auto body shops l Coating operations City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-34 September 2020 ICF 0662.19 l Fiberglass manufacturers l Foundries l Rendering plants l Livestock operations There are sensitive receptors within 1,000 feet of the project site, but the project would not include new sensitive receptors. As discussed above, the California Supreme Court has opined that impacts of the environment on projects are not subject to CEQA analysis, with limited exceptions. This general rule includes the impacts of existing odor-generating uses on future land uses. None of the above land uses are within 1 mile of the project site. The proposed project does not propose any changes that would affect odor-generating facilities. Therefore, odor complaints regarding existing odor-generating facilities are not anticipated upon implementation of the proposed project. The potential odor-generating land uses identified above are generally not allowed under the City’s existing Gateway Specific Plan District (commercial and research-and-development) zoning designations, as would continue to be the case with approval of the proposed project. The proposed project would not expressly encourage these uses or a substantial increase in the amount of land zoned for such uses. In addition, because the proposed project would be required to comply with the local zoning ordinance, odor-generating uses would be developed only in areas that are zoned for such uses, and would not be included in the proposed project. Potential odor emitters during construction include diesel exhaust, asphalt paving, and the use of architectural coatings and solvents. However, construction-related operations would be temporary and would not be likely to result in nuisance odors that would violate BAAQMD’s Regulation 7. Odors during operation could emanate from vehicle exhaust and the application of architectural coatings. These odors would be limited to areas adjacent to the building. Although such brief exhaust- and paint-related odors may be considered adverse, they would not affect a substantial number of people. Given mandatory compliance with BAAQMD rules, none of the proposed construction or operational activities would create a significant level of objectionable odors. Therefore, odor impacts would be less than significant. No mitigation is required. 4.2.4.4 Cumulative Impacts The cumulative geographic context for air quality is the SFBAAB. The cumulative geographic context for health risks and odors is the immediate vicinity of the project site (i.e., 1,000 feet). Cumulative projects within 0.5 mile (2,640 feet) of the project site are described in Section 4.1.5, Approach to Cumulative Impact Analysis, of this draft EIR and shown in Figure 4.1-1. Impact C-AQ-1: The proposed project in combination with past, present, and reasonably foreseeable future projects would not result in a cumulatively considerable impact on air quality plan consistency. (Less than Significant) As discussed under Impact AQ-1, the proposed project would support the goals of BAAQMD’s Clean Air Plan, would include all applicable control measures, and would not conflict with Clean Air Plan implementation. The purpose of the Clean Air Plan is to improve regional air quality in the air basin; therefore, the analysis and less-than-significant finding under Impact AQ-1 is inherently cumulative. For these reasons, the proposed project in combination with past, present, and reasonably foreseeable future projects would not result in a significant cumulative impact related to air quality plan consistency. The cumulative impact would be less than significant. No mitigation is required. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-35 September 2020 ICF 0662.19 Impact C-AQ-2: The proposed project would not result in a cumulatively considerable contribution to significant cumulative impacts related to a net increase in criteria pollutants for which the region is in nonattainment for an applicable federal or state ambient air quality standard. (Less than Significant with Mitigation) As discussed above, BAAQMD has identified project-level thresholds to evaluate criteria pollutant impacts (Table 4.2-4). In developing these thresholds, BAAQMD considers levels at which project emissions are cumulatively considerable. As noted in BAAQMD’s guidelines, In developing thresholds of significance for air pollutants, BAAQMD considered the emission levels for which a project‘s individual emissions would be cumulatively considerable. If a project exceeds the identified significance thresholds, its emissions would be cumulatively considerable, resulting in significant adverse air quality impacts on the region’s existing air quality conditions. Therefore, additional analysis to assess cumulative impacts is unnecessary. Exceedances of project-level thresholds would be cumulatively considerable, and the cumulative impact would be significant. As discussed under Impact AQ-2, construction of the proposed project would not generate ROG or PM emissions in excess of BAAQMD’s numeric thresholds. However, the proposed project would generate NOX in excess of BAAQMD’s daily threshold. Implementation of Mitigation Measure AQ-1, Use of Clean Diesel-Powered Equipment during Construction to Control Construction-Related NOX Emissions, would reduce NOX emissions to a less-than-significant level (see Table 4.2-6). In addition, Mitigation Measure AQ-2, Implement BAAQMD Basic Construction Mitigation Measures, would require construction within the project site to implement BMPs as recommended by BAAQMD to reduce fugitive dust emissions to less-than-significant levels. As discussed above, air quality impacts would be below BAAQMD’s numeric thresholds during operation. Accordingly, the proposed project’s contribution to a cumulative criteria pollutant emissions impact would be less than cumulatively considerable with mitigation. Impact C-AQ-3: The proposed project in combination with past, present, and reasonably foreseeable future projects would not contribute to cumulative health risks for sensitive receptors. (Less than Significant with Mitigation) The project at 475 Eccles Avenue (Cumulative Project No. 16), which would involve new office/R&D buildings, is the only cumulative project located within 1,000 feet of the project site. There are no sensitive receptors within 1,000 feet of 475 Eccles Avenue. Construction and operation of the project at 475 Eccles Avenue would generate TACs but would be reduced with distance from the site and BAAQMD’s regulatory mechanisms for stationary sources, respectively. In addition, the proposed project would involve construction activities and locate a new diesel- fueled generator on the project site, generating DPM and PM2.5. There are existing nearby DPM and PM2.5 sources within 1,000 feet of the project site which, along with the proposed project, could contribute to a cumulative health risk for existing sensitive receptors at the Gateway Child Development Center Peninsula. This is a potentially significant impact. BAAQMD data files and distance multipliers provided by the BAAQMD were used to estimate the background impacts and concentrations for existing stationary, roadway, and rail sources. The combined risks from construction and operation of the proposed project and ambient sources are summarized in Table 4.2-10. The methods used to estimate project emissions are described above in Methods for Analysis and supplemented with more detail in Appendix B. City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-36 September 2020 ICF 0662.19 Table 4.2-10. Maximum Mitigated Cumulative Health Risks from the Proposed Project Source Cancer Risk (case per million) Non-Cancer Hazard Index Annual PM2.5 Concentration (μg/m3) Contribution from Existing Sourcesa Stationary Sources 6.7 0.07 0.04 Roadway Sources 14.0 - 0.29 Rail Sources 21.6 - 0.04 Contribution from Project Constructionb Gateway Child Development Center Peninsula 0.6 <0.01 <0.01 Contribution from Project Operation Gateway Child Development Center Peninsula 0.1 <0.01 <0.01 Cumulative Totals Existing + Construction 42.8 0.07 0.37 Existing + Operation 42.4 0.07 0.37 Existing + Construction + Operation 43.0 0.07 0.37 BAAQMD Thresholds 100 10 0.8 Source: See Appendix B for modeling outputs and calculations. Notes: μg/m3 = micrograms per cubic meter a Contribution from existing sources represent the health risks within 1,000 feet of the maximum exposed receptor at the Gateway Child Development Center Peninsula. b Contributions from project construction reported with implementation of construction mitigation measures. As shown in Table 4.2-10, cumulative risks and concentration levels of existing sources (i.e., stationary, roadway, and rail sources) do not exceed BAAQMD’s cumulative thresholds. Implementation of Mitigation Measures AQ-1 and AQ-2 would reduce risks and concentration levels associated with construction (e.g., diesel particulate matter, PM2.5 exhaust, PM2.5 fugitive dust) of the proposed project and the the combined total cumulative cancer risks and hazard impacts would continue to not exceed the BAAQMD’s cumulative thresholds. As such, there would be no significant cumulative impact from exposure to health risks associated with TACs. For these reasons, the proposed project, in combination with other past, present, and reasonably foreseeable future projects, would not result in a significant cumulative impact. The cumulative impact would be less than significant with mitigation. Impact C-AQ-4: The proposed project in combination with past, present, and reasonably foreseeable future projects would not contribute to emissions (such as those leading to odors) adversely affecting a substantial number of people. (Less than Significant) The project at 475 Eccles Avenue (Cumulative Project No. 16), which would involve new office/R&D buildings, is the only cumulative project located within 1,000 feet of the project site. These land uses are not commonly associated with odors and there are no sensitive receptors or odor-generating facilities within 1,000 feet of 475 Eccles Avenue. Construction of 475 Eccles Avenue would generate odors from diesel exhaust, asphalt paving, and the use of architectural coatings and solvents, but City of South San Francisco Environmental Setting, Impacts, and Mitigation Air Quality 751 Gateway Boulevard Project 4.2-37 September 2020 ICF 0662.19 activities would be temporary and would not result in nuisance orders that would violate BAAQMD’s Regulation 7. The project at 475 Eccles Avenue would not affect the operation of odor-generating facilities. In addition, as discussed under Impact AQ-4, the proposed project would not generate substantial odors. For these reasons, the proposed project, in combination with other past, present, and reasonably foreseeable future projects, would not result in a significant cumulative odor impact. The cumulative impact would be less than significant. No mitigation is required.